Cherax species novel (new crayfish species)

Identification

Cherax species novel

A new crayfish species was recently discovered in 2020 through a genetic survey of crayfish in south-west Western Australia. This survey was a collaborative project between the department and Edith Cowan University (School of Science). The crayfish is yet to be formally described, for the purpose of this web summary it will be referred to as Cherax species novel.

This crayfish is very similar in appearance to the restricted gilgie (Cherax crassimanus).

Colour varies from light to dark greenish brown, generally with distinctive mottling and can have a light brown/orange central stripe and reddish-orange colourings on the basal portion of legs. A covering of fine hairs are sometimes present on the exoskeleton, but not on all occasions.

It is distinguished from other crayfish based on weight-of-evidence considering the following:

  • Four obvious keels on the head with a reduced central keel (gilgie and marron have 5 keels, and typically more pronounced, and the koonac and glossy koonac have 4 keels);
  • A telson without spines (marron have 2 obvious telson spines);
  • A more acutely, anteriorly-curved and sharper spine on the inner edge of the wrist compared to the gilgie and koonac species.
  • Distribution range (Denmark to Albany catchments, noting that the characteristically similar restricted gilgie was not recorded in this area)

Maximum total length (rostrum to tail) is approximately 70 mm (based on current specimens).

Distribution

The current known distribution extends from Denmark to Albany.

Habitat

Occupies both permanent and ephemeral streams, however generally appears to prefer smaller, shallow systems.

Biology

The biology of this species has not been studied.

Further information

Contact the Departments River Science team.